A number of processes for the production of 1,1,1-trifluoroethane (HFC-143a) are known. However, the products of these processes contain reaction by-products, among which is 1-chloro-2,2,2-trifluoroethane (R-133a). It is highly desirable to be able to remove such reaction by-products in order to achieve purer 1,1,1-trifluoroethane or a 1,1,1-trifluoroethane compositions having a boiling point within a relatively small range.
Unfortunately, as is known to those in the relevant art, the combination of two or more constituents forming an HFC/non-HFC mixture often results in compositions wherein relatively small changes in the relative amounts of the constituents results in relatively large changes in the boiling point and vapor pressure of the mixture. For example, the boiling point and vapor pressure characteristics of many typical HFC/non-HFC mixtures can be predicted using Regular Solution mathematical models as described in Praunitz, Lichtenthaler, Azevedo “Molecular Thermodynamics in Fluid-Phase Equilibria”, pp 179-190 (second edition), Prentice-Hall, Inc., incorporated herein by reference thereto. As illustrated by Prausnitz et al., a plot of vapor pressure or boiling point of a regular solution versus it's constituent composition tends to have a significantly positive slope, indicating that relatively large changes in vapor pressure or boiling point occur upon relatively small changes in the constituent composition. Accordingly, mixtures having only relatively small differences in constituent amounts may still have relatively large changes in boiling points. Thus, there is a need to identify a binary azeotropic or azeotropic-like mixture of HFC-143a and R-133a so that modeling and simulation may be accomplished to identify the correct necessary separation equipment and methods to better obtain purities of final HFC-143a product.